The User's Manual is one of four manuals that constitute the documentation for NASTRAN, the other three being the Theoretical Manual, the Programmer's Manual and the Demonstration Problem Manual. Although the User's Manual contains all of the information that is directly associated with the solution of problems with NASTRAN, the user will find it desirable to refer to the other manuals for assistance in the solution of specific user problems. The Theoretical Manual gives an excellent introduction to NASTRAN and presents developments of the analytical and numerical procedures that underlie the program. The User's Manual is instructive and encyclopedic in nature, but is restricted to those items related to the use of NASTRAN that are generally independent of the computing system being used. Computer-dependent topics and information that is required for the maintenance and modification of the program are treated in the Programmer's Manual. The Programmer's Manual also provides a complete description of the program, including the mathematical equations implemented in the code. The Demonstration Problem Manual presents a discussion of the sample problems delivered with NASTRAN, thereby illustrating the formulation of the different types of problems that can be solved with NASTRAN. Volume 2, Section 1 contains a general description of rigid format procedures. Specific instructions and information for the use of each rigid format are given in Volume 2, Sections 2, 3 and 4, which deal with the rigid formats associated with the DISPLACEMENT, HEAT and AERO approaches, respectively.